I personally like Madelyne Pryor, but I wouldn't want to bring her into the movies anytime soon honestly. I don't think she's that convoluted herself, but yes some things she's done in the comics regarding Cable does show her involving other characters easily becomes a mess, and honestly with as large a cast as they can have, they really don't need to bring in new characters until they solidify whats going on with the characters they have to choose from.